Researchers preparing to open fragile 300-year-old caskets from St. Mary's Archaeologists may open caskets, thought to contain Calverts, at Dover Air Force Base.

Mortuary facilities at Dover Air Force Base, Del., used since the Vietnam War to process the remains of America's war dead, may soon be pressed into the service of colonial archaeology.

Henry Miller, chief archaeologist for Historic St. Mary's City, said that, pending final approvals, three 300-year-old lead caskets thought to contain the remains of members of Maryland's founding Calvert family will "probably" be opened at Dover as early as next spring.

"According to our forensic experts," Miller said, the Dover mortuary "is one of the finest in the world."

There, the fragile caskets can be opened under carefully controlled environmental conditions to protect their contents.

If enough human tissue has survived the centuries, scientists hope to conduct state-of-the-art genetic and forensic tests to help identify the people buried in the caskets, what they looked like, and how they lived and died.

The lead caskets were discovered last year beneath a meadow covering the ruins of the Great Brick Chapel in St. Mary's City, Maryland's first colonial capital. The church was built around 1667 and demolished in 1705.

The largest coffin is thought to contain the remains of Philip Calvert, who died in 1682. He was Maryland's first chancellor and a half-brother to Cecil Calvert, Lord Baltimore.

Miller has said a smaller lead casket found buried beside the first may contain Philip's grandnephew, Cecil, who died in 1681 at the age of 14. The third casket, sized for a small child, may hold the remains of one of several other children of Charles Calvert, Cecil's father.

After they were first uncovered last December, the caskets were reburied while Historic St. Mary's City assembled a panel of experts to map a high-tech strategy for studying the caskets and identifying whatever remains they contain.

The preparations, Miller said, have been "like planning for D-Day."

The first challenge, Miller said, has been to determine how to handle the coffins by learning how they were built in the 17th century.

A small model coffin was crafted by Mark Moore, of the Armed Forces Radio-Biology Institute in Bethesda, and is now being tested at the National Aeronautics and Space Administration's Langley Research Center in Virginia "to figure out how strong these coffins are," Miller said.

"We modeled it from the data I collected in the field from the smaller of the three lead coffins," he said. "We learned a lot about how they couldn't have been built."

The scientists also were able to estimate the weights of the three caskets. The biggest, Miller said, contains close to 1,000 pounds of lead. The smallest has perhaps 120 pounds of lead.

In an effort to learn more, Miller's panel had hoped to study the 221-year-old lead coffin of one of Virginia's colonial governors, buried in Williamsburg.

"We hoped to do ultrasonic testing and some eddy current [electrical] testing to figure out how they were built and what certain structural features look like under ultrasonics, so that we can better understand what we may be getting into."

But the study was called off last month when the Williamsburg crypt proved to be dangerously contaminated by asbestos insulation. Miller hopes the work can be salvaged by winning access to another colonial gravesite.

By January, Miller said, a tent or building will be erected over the chapel site to help dry the soil and protect the excavation. Navy Seabees from Annapolis have offered to do the work.

"Probably in late February, we will start the excavations to get the work area cleared and get down to the layer where the coffins are," he said. "In March, we'll do the uncovering."

Once the coffins are exposed, scientists will conduct a battery of remote-sensing tests to determine the condition of the coffins and their contents.

"NASA people have been urging us to wait another year or more" until a new sensing device is fully developed, Miller said. "But we can't wait that long."

Scientists will then pierce the coffins, flood the interiors with inert argon gas and draw off for study any 17th-century air trapped inside.

Donated medical fiber-optic devices will be used to peer into the caskets to determine the condition of any remains.

If the coffins can be safely moved, Miller said, a rigid box will be built around them, with suction devices to support the lead and prevent its collapse. Then they will be lifted from the crypt where they have lain for more than 300 years.

The Patuxent Naval Air Station may be called on to help build the lifting devices, Miller said.

After they are moved to Dover in a cushioned truck, the coffins will be placed in a controlled atmosphere to exclude modern contaminants. If the remains are intact, the coffins will be opened like lunar rock samples -- in an inert, oxygen-free atmosphere by remote-controlled devices, or by technicians working in airtight suits.

It's a painstaking, costly process, Miller said, "but it has to be done, and we have to do it thoroughly or we shouldn't do it at all."

The total budget for the work is expected to be completed later this month, after which the search for financial backing will begin.

The project has already drawn national attention and offers of donated equipment and services. It may also draw financial support from major scientific and educational foundations.